Beverage compositions, for example, soft drink beverages (e.g., cola beverages) and fruit juice beverages, have the potential when consumed to cause dental erosion and often dental discoloration. Such dental erosion and discoloration can result wherein the beverage composition is acidic in nature, i.e., exhibits a pH of about 5 or below. Additionally, since children are particularly susceptible to dental erosion relative to adults due to the smaller enamel surface to volume ratio, consumption of such beverages may be of particular concern for this group. Accordingly, since many consumers ingest acidic beverage compositions weekly, daily, or even more frequently, it would be advantageous to discover a beverage composition that protects against dental erosion and discoloration.
The art suggests that such factors as pH, fluoride, calcium, and even phosphate concentration may have an effect on dental erosion and/or dental caries. For example, acidic pH, particularly about 5 or below, is typically considered to exacerbate dental erosion (which occurs by direct action of acid on the enamel surface). For example, Lussi et al., “Prediction of the Erosive Potential of Some Beverages”, Caries Research, Vol. 29, pp. 349-354 (1995) examined the erosive potential of many beverage compositions, all having a pH of less than 5.
Furthermore, Borggreven et al., “The Influence of Various Amphiphilic Phosphates on in vitro Caries Lesion Formation in Human Dental Enamel”, Caries Research, Vol. 26, pp. 84-88 (1992) suggests enamel softening in the presence of certain polyphosphates at levels below pH 5.5. See Borggreven et al., p. 87.
The art suggests that further factors are important in dental erosion and/or dental caries. Lussi et al. (citation herein above) suggests that fluoride concentration is a further factor contributing to dental erosion. For example, among beverage compositions tested by Lussi et al., the compositions having the highest fluoride concentrations showed the smallest amount of surface softening of the enamel. However, highest phosphate concentrations did not necessarily correlate with decreased surface softening of the enamel. For example, apple juice, having a moderately high phosphate concentration relative to many other beverage compositions tested, was also the most erosive beverage composition tested. See Lussi et al., pp. 352-353.
There has been further experimentation with certain phosphates, including pyrophosphates and polyphospates, with respect to dental health, particularly in the area of dental caries. For example, Städtler et al., “The Effect of Sodium Trimetaphosphate on Caries: A 3-Year Clinical Toothpaste Trial”, Caries Research, Vol. 30, pp. 418-422 (1996), suggests that trimetaphosphate (a cyclic phosphate) may be effective against dental caries. However, Städtler et al. utilized toothpaste formulations having near-neutral pH rather than a more acidic formulation. Other studies have suggested efficacy against dental caries using certain phosphates in a relatively neutral pH, calcium-containing solution, but the “polyphosphates” studied comprised 2, 3 or 6 phosphates (ortho, trimeta, tripoly, and hexameta phosphates). See e.g., McGaughey et al., “Effects of Polyphosphates on the Solubility and Mineralization of HA. Other studies of the effect of small polyphosphates (P<6) on dental caries include: Relevance to a Rationale for Anticaries Activity”, Journal of Dental Research, pp, 579-587, June 1977 and Shibata et al., “Antibacterial Action of Condensed Phosphates on the Bacterium Streptococcus Mutans and Experimental Caries in the Hamster”, Archives of Oral Biology, Vol. 27, pp. 809-816 (1982).
Another study did suggest the efficacy of monocalcium phosphate in low pH powdered beverage compositions for preventing molar erosion. See Reussner et al., “Effects of Phosphates in Acid-Containing Beverages on Tooth Erosion”, Journal of Dental Research, pp. 365-370, March-April 1975. However, this same study further suggested that beverage compositions supplemented with other phosphates, including sodium hexametaphosphate, did not produce significant protective effects against molar erosion. See Reussner et al., p. 367. These studies generally agree that the tripoly phosphate (P=3) has some benefit for preventing caries. But these studies fail to identify larger polyphosphates that protect teeth from the harmful effects of acidic beverages.
Finally, WO 01/72144 A1, filed by Smithkline Beecham PLC, and claiming priority to a Great Britain application filed on Mar. 27, 2000, discloses the use of longer chain poly phosphates (n=7 to 30) for use in acidic oral compositions (pH between 2.5-5.5) to alleviate tooth damage. This reference, however, does not discuss or contemplate the delivery of higher chain polyphosphates from a non-acidic beverage composition.
Accordingly, there is a continuing need for beverage compositions having a relatively neutral pH, which are effective against dental erosion and discoloration. More specifically, there is a need for beverages that are not acidic enough to attack teeth, but provide protection from the harmful attack of acidic beverages. Moreover, there exists a need for beverages that protect teeth from both erosion and discoloration. These and other benefits are provided by the present invention.